Signal lamp



Oct. 4, 1955 H. B. DONLEY 2,719,967

SIGNAL LAMP Filed July 18, 1952 1N VEN TOR.

A TTORNE Y United States Patent Office 2,719,967 Patented Oct. 4, 1955SIGNAL LAMP Harold B. Douley, Columbus, Ohio, assignor to Columbus MetalProducts, Inc., Columbus, Ohio, aV corporation of Ohio t ApplicationJuly 18, 1952, Serial No. 299,569

6 Claims. (Cl. 340-382) My invention relates to `lamps and moreparticularly to an improvement in lamps for vehicles.

An object of the present invention is to provide `a` signallamp forvehicles wherein objectionable glare is prevented from striking thedrivers eyes by a light interrupting element which is positioned tointerrupt certain `directionally uncontrolled rays which would normallybe emitted from the lamps.

A further object of the present invention is to provide a signal lampfor vehicles wherein a phantom light effect, produced by external lightentering the lamp, is minimized by alight interrupting element.

`Still a further object of the present invention is to provide means formounting such light interrupting element in a signal lamp. j

The present invention is particularly useful on trucks where it iscommon practice to mount a turn signal lamp at the apex of each frontfender. Each light generally comprises a forwardly directed reflectorand a rearwardly directed reflector with the two reflectors having acommon light bulb.

Prior to the present invention, certain objectionable characteristicshave been present in signal lamps of this type. As certain of theemitted rays from the light bulb pass directly through a lens of thelamp without first contacting a reflector, such rays are not presentedtothe lens in a parallel beam. The reflectors used are of the parabolictype which collimate certain of the light rays and present them to alens in a beam of parallel rays. Hence the lenses used are ofthe typedesigned to directionally control light received in collimated form.Such lenses are therefore necessarily not of the proper design fordirectionally controlling certain of the light rays which are radiallyemitted from the light source and which pass directly through a lenswithout first contacting a reflector. Certain of these rays, which passdirectly from the light source to a lens, are naturally directed toobliquely strike the inner surface of the lens. Heretofore such rayshave been permitted to pass through the lens with the objectionableresult that some of such rays were directed upwardly by the prismaticeffect of the lens causing glare in the drivers eyes. With the presentinvention, however, the drivers eyes are protected from glare bypositioning a light interrupting element or shield in the ray pathbetween the light source and the lens. Such shield is positioned betweenthe lens and the light source, as herein disclosed, so as not tointerfere with the normal function of the lamp.

A second objectionable characteristic heretofore present in lamps ofthis type has also been materially eliminated by the shield justdescribed. In signal lamps of the type having a common light bulbbetween forwardly `directed and rearwardly directed lenses andreflectors, it

is possible for external light, such as sunlight, to enter the signalthrough a lens and cause the signal to appear to be` illuminated,particularly when the other lens is viewed by an approaching driver.This artificial illumination, on occasion, indicated false signals, suchas incorrect signals of turn, to approaching drivers, and avoidableaccidents have resulted. Such artificial :illumination will be hereinreferred to as the phantom light.`

The shield of the present invention serves to prevent a major portion ofthe external light rays, which strike a lens, from passing into the turnsignal and thereby materially minimizes the phantom light effect in thesignal. When the sun is low, as at setting, the rays may become alignedwith the aXis of the shield so that the shield becomes less effective,but at such period of the day, the need for the shield is greatlylessened due to the decreased intensity of the suns rays. Hence, as apractical matter, the present device serves to eliminate the phantomlight effect from turn signals of the double reflector type. At the sametime, the present invention also serves to shield the drivers eyes fromobjectionable glare.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred form of embodiment of the invention isclearly shown.

` In the drawings:

Fig. l is a side view, partially in section, of a signal lightconstructed in accordance with the present invention with the sectionbeing taken essentially along the line 1 1 of Fig. 2; j

Fig. 2 is a front View, partially in section, of the signal light ofFig. l with the section being taken essentially along the line 2 2 ofFig. l; and 4 Fig. 3 is a broken sectional view showing the means formounting the shield of the present invention.

Referring to the drawing the signal lamp comprises a casing 10 in whicha light bulb 11 is mounted in a socket 12. Two reflectors 13 are shown,and in the presentV embodiment are disposed opposite one another andWithin the casing 10. The reflectors are positioned so that the bulb 11serves as a common light source for casting light upon the surfaces 14of the reflectors. Each of the reflectors is preferably of parabolicconfiguration and the two reflectors are positioned so that the fociofthe parabolas are coincident. The light source 11 is preferablylocated at the common focal point for the two parabolas. With suchpreferable configuration, the light reflected from the surface 14 willbe collimated sothat` the reflected light reaches a lens 15 in parallelrays.`

I'JIwo of such reflected rays are shown at A and B in As the lightsource 11 emits rays in all directions, certain of the rays, which arenot directed towards a reilector, will pass directly to a lens 15.Referring to the left side of Fig. l, the ray D will be seen passingdirectly from the source to the lens.` The same would ordinarily be trueof certain other rays such as ray C, but since a shield 18 is mounted inthe lamp, the normal path of ray C is interrupted at the point where-`ray C strikes the inner surface of the shield 18. The extension of ray Cbeyond the shield 18 is indicated by short dot segments to show theoriginal path that ray C would follow if it were not deflected by theshield 18.

It should be noted that the rays C and D are not collimated by thereflector, as were the rays A and B, and hence such former rays will bepresented to the lens at an oblique angle. Light ray C is provided as atypical illustration of an uncontrolled ray which would produce anobjectional effect were the shield 18 not present. The

normal path of the light ray C is seen to be bent sharply wall of theshield at a slot 21a.

3 prismatic effect of the condensing by collimating portion of the lensto substantially align the path of ray D with the path of the controlledrays A and B.

The direct ray C exemplifies the light rays, that are uncontrolled bythe ref iector and lens combination which is necessarily designed fordirectionally controlling the reected light rays, and hence is of animproper design for controlling certain rays, such as ray C, which areemitted directly from the source to the peripheral portion of the lenssurface.

As the signal lamp of the present invention is preferably mounted on theapex of a v'ehicles fender, certain of the direct rays, which aredirected upwardly at a sharp angle as exemplified by the normalV path ofray C, will cause glare in the eyes of the driver of the vehicle. Toeliminate, this glare, a light interrupting element, or shield 18 isinterposed in the path of the light rays so that the wall of the shieldwill blank out the objectionable upwardly directed rays such as ray C ofthe drawing. With the shield 18 positioned as shown i. e. surroundingthe collimating section of the lens, the reflected` raysand certain ofthe direct rays that pass centrally through the lens, are not deected bythe shield 18. Hence the total illumination potential of the light isonly slightly lessened by the presence of the shield 18. At the sametime, the direct rays which could produce objectionable glare areinterrupted by the shield.

Although the shield 18' is shown in the drawing as a tubular element,such tubular shape merely represents a preferred configuration. Theillustrated shield can be replaced by' a shield having any othersuitable form whereby the objectionable rays are deflected in the mannerdescribed herein.

The outer end of the shield 18 preferably extends to the inner surfaceof the lens 15, and the shield` is pref'- erably made of sufficientlength so that the inner end of the shield terminates at the path of rayH as shown in Fig. l. In this manner, all of the objectionable directlyemitted rays which are lower than ray H, such as ray C, will bedeflected by the shield 18. At the same, time, all` of the rays aboveray H, such as rays A and B, will passV to the reector surface, or willat least be prevented from passing directly out through the upperportion of the lens to produce glare in the drivers eyes.

Referring particularly to the reiiector and lens shown on the right sideof Fig. l, a ray E of light from an external source is shown passinginto the light through the lens a. Such external rays will strike theglass ofthe bulb 11 and the glass of the lens 15, and such rays arediffused by the glass causing such glass to appear to be illuminated byan interior light source. I t should be noted that the externall rays Eare free to pass through the apertures 2,5 inthe rear walls of thereectors. Hencethe external rays can enter the lamp throughV one lensand pass through the lamp to the other lens. When the external light isof suflicient intensity, such rays, exemplified by ray E, produce aphantom light effect in the lamp so that such lamp appears to b eilluminated when viewed by an approaching driver. false signal willv begiven` and an accident may well be caused. The shield reduces theintensity of the natural lightentering through the lens 15aY of thelamp, and such shield deflects the external light rays which areobliquely presented to the lens 15a, andV thereby prevents suchexternalv rays from passing directly through the lamp. Such oblique raysare exemplifiedv by rays F and' G in Fig. 1.

The shields 18 are preferably mounted by a plurality" of radiallyextending mounting brackets 20. Such brackets are preferably in the formof` resilient wires- Each wire is provided with a hook- 251- whichengages the As isr shown inthe enlarged view of Fig. 3, each wire 20 isprovided with an end portion 22 which extends between an inner surface25' on the lens and a lens mounting surface 24 on the casing. The endportion 2.2` of the wire 20- is normally In this manner a bowed in themanner shown so that such end portion 22 is normally not aligned withthe surfaces 25 and 26. A clamping ring 27 is provided for mounting thelens to the casing. As is best seen in Fig. 3, the clamping ring 27 isof U-shaped cross section, with leg members 28 spaced progressivelyfarther apart towards their ends. Hence when the clamping ring 27 istightened by a bolt and nut 30, Fig. 2, the ring will force the surface25 on the lens towards the surface 24 on the casing. When the lens movestowards the casing, the bowed end portion 22 of wire 2t) is clamped intocomplete alignment and contact with the surface 25 on the lens. The endportion 22 is permitted to conform with the surface due to its inherentresiliency. The tightened position of the clamping ring 27 is shown inFig. 1,l and the normally bowed end portion 22 is shown clamped intoalignment with surfaces 24 and 25. In the tightened position of Fig. l,the wire 20 serves as a spring to constantly urge the shield 18 snuglyagainst the lens. Hence i-t is seen that the shield is mounted in asimple manner, which facilitates its assembly in the lamp. At the sametime the shield is held firmly in place by the spring action of wire20.*

As is best seen in Fig, 3, a gasket 26 is included be-v tween thesurfaces 24 and 25 to serve as a weather seal. The reflector 13 ispreferably mounted by clamping a peripheral portion 31 between thegasket 26v and the surface 24..

In summary7 itV will be seen that the shield of the presf ent inventionprovides novel improvements in signal' lamps. The functionalA di'erencesresulting from such improved structures are likewise novel, and theyexerrt` plify a meritorious advancement in the art.

While the form of embodiment of the present invention as hereindisclosed constitutes a preferred form, it is to be understood thatother forms might be adopted, all coming within the scope of the claimswhich follow.

I claim:

l. A lamp comprising in combination, a casing having an opening therein;a lens filling said opening; a reflector mounted in the casing; a lightsource adjacent to the reflector and positioned so that rays, directlyemitted from. the source, are emitted towards the entire area of thelens, said light source being positionedy such that Other rays impingeupon the reflector, said lens having a section for substantially'collimating direct rays emitted from thelight source, said lens having asecond section adjacent to the collimating section;l and a hollow lightinterrupter surrounding the collimating section of the lens and ex`tending axially inwardly from the lens and from the boundary of saidcollimatingI sectionl and toward the light source a distance sufficientto prevent direct rays, emitted from the lightV source, fromv impingingon said second section of the lens.

2. A lamp comprising incombination, a casing having an opening therein;a lens filling` said opening; a. reflectormounted in the casing; a lightsource adjacent to thelight source and terminating at an imaginaryconical sur-A face generated by straight li'nes extending from the lightsource to the periphery of the lens.

3. A lamp comprising in combination, a casing having an opening therein;a lensfillingI said opening; a re'ector mounted in the casing; a lightsource adjacent tothe re.-

iiector and positioned so that rays, directly emitted from' w thesource, are emitted towards the entire area of' the. lens, said lightsource being positioned such that other rays impinge upon the reflector,said lens having a section for substantially collimating direct raysemitted from the light source, said lens having a second sectionsurrounding the collimating section; and a tubular light interruptersurrounding the collimating section of the lens and extending axiallyinwardly from the lens and from the boundary of said collimating sectiontoward the light source a distance sufiicient to prevent direct rays,emitted from the light source, from impinging on said second section ofthe lens.

4. A lamp comprising in combination, a casing having two openings; alens filling one of said openings; a parabolically shaped reflectormounted in the casing, the rear of said reflector having an openingtherein; a light source adjacent to the reflector and positioned so thatrays, directly emitted from the source, are emitted towards the entirearea of the lens, said light source being positioned such that otherdirect rays from the light source impinge upon the reflector and stillother rays pass through the other of said openings in the casing, saidother opening in the casing being so positioned that light rays from anexterior source could pass therethrough and through the opening in thereflector to the lens, said lens having a section for substantiallycollimating direct rays emitted from the light source, said lens havinga second section adjacent to the collimating section; and a hollow lightinterrupter surrounding the collimating section of the lens andextending axially inwardly from the lens and from the boundary of saidcollimating section toward the light source, a distance sufficient toprevent direct rays, emitted from the light source, from impinging onsaid second section of the lens.

5. A lamp comprising in combination, a casing having two openings; alens lling one of said openings; a lens filling the other of saidopenings; a parabolically shaped reliector mounted in the casing incooperative relation with one of the lenses; a second parabolicallyshaped reflector mounted in the casing in cooperative relation with theother of the lenses, the rear of each refiector having an openingtherein; a light source adjacent to both openings and positioned so thatrays, directly emitted from the source, are emitted towards the entirearea of each of said lenses, said light source being positioned suchthat other of the direct rays of the light source impinge on one or theother of said reflectors, said openings in the casing being sopositioned that light rays from an exterior source, passing through oneof said lenses, illuminates the other lens, said lenses each having asection for substantially collimating direct rays emitted from the lightsource and a second section adjacent to the collimating section; and twohollow light interrup'ters, one of said interrupters surrounding thecollimating section of one of the lenses, the other interruptersurrounding the collimating section of the other of said lenses, each ofsaid interrupters extending axially inwardly, lrespectively, from a lensand from the boundary of the collimating section of such lens to thelight source, a distance sufficient to prevent direct rays, emitted fromthe light source, from impinging on the second mentioned section of theleus from which it inwardly extends.

6. A lamp such as that defined in claim 5 in which the lenses, theopenings in the reflectors and the hollow interrupters are axiallyaligned.

References Cited in the lile of this patent UNITED STATES PATENTS1,096,452 Perrin May 12, 1914 1,194,758 McCarthy Aug. 15, 1916 1,266,524Otte May 14, 1918 1,675,731 Schofield July 3, 1928 2,058,546 Haines Oct.27, 1936 2,243,448 Wells May 27, 1941 2,327,144 Stam Aug. 17, 1943

